Binder or "mortar" compositions of the type contemplated by the present invention are broadly disclosed in U.S. Pat. No. 3,240,736. The prior known methods for preparing such compositions comprise preparation of a mixture of (a) cement, plasticizer (i.e., latex) and water and a separate mixture of (b) resin and curing agent, followed by prompt admixing of the separately formed mixes. Such process requires that the ingredients of the binder composition be supplied to the user as a four-package system, i.e., individual packages of cement, plasticizer, resin and curing agent. Heretofore, these ingredients could not be premixed and stored without adversely affecting the binder properties. It is the primary object of the present invention to provide a means of forming such binder compositions wherein the ingredients thereof may be premixed and supplied to the user as a two-package system without detriment to binder effectiveness.